“Stop!” André commanded, for Onslow was very near the stove and the letter was very precious.

“For five minutes only,” Onslow retorted. “Give me your word of honour that you will let me go free and you shall have the letter—or I destroy it and fight for my life as best I can. Make up your mind, Vicomte.”

The clock ticked very loud and clear while André weighed the issues. The letter was precious; it was there, which the despatch was not; time was more precious still, for there remained “No. 101” to be dealt with. Onslow’s life was of no value to Denise or himself. André studied the secret agent’s calm face for three silent minutes.

“Give me the letter,” he said at last, “you shall go free, on my word of honour.”

“I thank you. But you have decided wisely.” Onslow placed the letter on the table. “And now,” he buttoned up his cloak, “kindly write me a pass, for I must leave your accursed city before dawn.”

“The password at the Barrier of the Hospital of St. Louis is, ‘La santé du Roi,’” André answered. “That will take you through in safety.”

Onslow bowed. “My compliments, Vicomte; your precautions devised at such short notice do you infinite credit. I fancy we shall meet again, but not in the salon of ‘the Princess’ either in Paris or London.”

André had moved towards the writing-table. “I had better write you a pass after all,” he said, very politely, “the police are not so scrupulous as I am about a pledge of honour.”

Onslow fell into the trap. Like many clever men who find a lie succeed beyond their expectations, he wholly misunderstood the motives that had persuaded the other to accept for truth what he feared was untrue. André had turned his back to write, but he had hardly scrawled three words when he wheeled with incredible swiftness.

“No!” he cried, “you don’t stab two men in the back unawares in one night, traitor and spy.”